This invention is concerned with improvements in or relating to the manufacture of shoes and is especially concerned with apparatus for and methods of attaching a sole to a shoe where the sole comprise an upwardly projecting portion intended to be stuck by means of adhesive to a portion of the upper of the shoe.
The word "shoe" where used herein is to understood as referring to footwear generally whether complete or in the course of manufacture.
In the shoe industry, the sole of a shoe is frequently secured thereto by means of adhesive. When this is done, the sole and the shoe are forced together in a sole-attaching press to allow the adhesive to form a strong bond. The sole is usually engaged by a pad or pads profiled to the shape of the sole and is pressed against the shoe bottom while the shoe is held against movement. The profiled pad or pads ensure that a substantially uniform pressure is applied throughout the tread area of the sole so that a substantially uniform bond is achieved throughout this area.
Where the sole to be attached engages only the bottom of the shoe to which it is to be attached, the present methods of attachment are generally satisfactory. However, certain kinds of shoe have soles with an "upwardly" projecting portion (i.e., a portion extending heightwise of the shoe and away from the tread surface of its sole) intended to be stuck to the upper of the shoe, and these create attachment problems because of the lack of pressure available for pressing this portion against the upper. An example of a shoe which has a sole with such an upwardly projecting portion is an athletic shoe where this portion provides a grip surface around the toe of the shoe.